question about your router jigs; i see where the pins line up, and where the cutout for the semi-circle is and all. Can you explain why you needed the semi-circular cut-outs in the jig?

The semi-circle helped register the jig on the 1st route (lines up with the circular hole). With that 1st route, I drilled the holes for the locating pins. The second routing template was then located precisely with the pins.